Researches show that blue light having a wavelength less than 435 nm will do a great harm to retina. There is an A2E component in a human retina. The absorption peak of the A2E is located at ultraviolet light 335 nm and visible blue light 435 nm, which is easy to perform photooxidation due to absorption of the blue light, to cause apoptosis, thus causing macular degeneration to human eyes. Moreover, the wavelength of the blue light is shorter, which is easy to cause scattering and dazzle light. The eyes need to focus harder. In the long run, the ciliary muscle is tired and aches, which causes pseudomyopia. In addition, excessive exposure in high energy blue light will affect the living clock of the human body, such that the human body suffers from endocrine dyscrasia and the risk of developing a cancer is increased. This is because that the high energy blue light will reduce the secretion of melatonin of the human body, while the melatonin is an active substance that controls the living clock and the endocrine of the human body. Moreover, the energy of the dark blue light received by the human eyes is 253 times of that of green-yellow light under the same perception luminance, so that the human eyes are hurt by the visible blue light with high energy insensibly.
Therefore, if excessive blue light having a wavelength less than 435 nm comes into the human eyes, the human eyes and an endocrine system will be hurt severely.
FIG. 1 is a light emitting spectrogram of a conventional liquid crystal display (LCD), wherein the energy of the blue light having a wavelength less than 435 nm is very great. However, 3C products (computer, communication and consumer electronics) used in life mostly relate to the foregoing light-emitting devices. As described above, using these displays for a long term will cause asthenopia and pseudomyopia, and more seriously, will even cause retinopathy and living clock disorders and the like.
In order to avoid the hurt of the high energy blue light to the human body, a manner mainly adopted in related art is to paste an anti-blue light protective film on the 3C products. FIG. 2 is a test pattern of UV transmittance of multiple existing protective films, wherein the five curves respectively represent transmittance curves for light having a wavelength of 300˜700 nm to pass through anti-blue light films under four different brands (i.e., Benks, JC, Wriol and ZC) and one tempered glass film without an anti-blue light function under the brand of ZC. It can be seen from the figure that about 25% high energy blue light can be suppressed by the anti-blue light protective films, but the transmittance at each wave band is decreased, so that the luminance of the display is affected to some extent.